166643421545216 has 432 divisors, whose sum is σ = 431785105339392. Its totient is φ = 63443887718400.

The previous prime is 166643421545203. The next prime is 166643421545287. The reversal of 166643421545216 is 612545124346661.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (56).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4157023925 + ... + 4157064011.

It is an arithmetic number, because the mean of its divisors is an integer number (999502558656).

Almost surely, 2^{166643421545216} is an apocalyptic number.

166643421545216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 166643421545216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (215892552669696).

166643421545216 is an abundant number, since it is smaller than the sum of its proper divisors (265141683794176).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

166643421545216 is a wasteful number, since it uses less digits than its factorization.

166643421545216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40816 (or 40795 counting only the distinct ones).

The product of its digits is 24883200, while the sum is 56.

The spelling of 166643421545216 in words is "one hundred sixty-six trillion, six hundred forty-three billion, four hundred twenty-one million, five hundred forty-five thousand, two hundred sixteen".